The 2002 NIMH Provisional Diagnostic Criteria for Depression of Alzheimer's Disease (PDC-dAD): Gauging their Validity over a Decade Later

Long Non-Coding RNAs and Alzheimer's Disease: Towards Personalized Diagnosis

Alzheimer's disease (AD), a neurodegenerative disorder characterized by progressive cognitive decline, is the most common form of dementia. Currently, there is no single test that can diagnose AD, especially in understudied populations and developing countries. Instead, diagnosis is based on a combination of medical history, physical examination, cognitive testing, and brain imaging. Exosomes are extracellular nanovesicles, primarily composed of RNA, that participate in physiological processes related to AD pathogenesis such as cell proliferation, immune response, and neuronal and cardiovascular function. However, the identification and understanding of the potential role of long non-coding RNAs (lncRNAs) in AD diagnosis remain largely unexplored. Here, we clinically, cognitively, and genetically characterized a sample of 15 individuals diagnosed with AD (cases) and 15 controls from Barranquilla, Colombia. Advanced bioinformatics, analytics and Machine Learning (ML) techniques were used to identify lncRNAs differentially expressed between cases and controls. The expression of 28,909 lncRNAs was quantified. Of these, 18 were found to be differentially expressed and harbored in pivotal genes related to AD. Two lncRNAs, ENST00000608936 and ENST00000433747, show promise as diagnostic markers for AD, with ML models achieving > 95% sensitivity, specificity, and accuracy in both the training and testing datasets. These findings suggest that the expression profiles of lncRNAs could significantly contribute to advancing personalized AD diagnosis in this community, offering promising avenues for early detection and follow-up.

Depression in Major Neurodegenerative Diseases and Strokes: A Critical Review of Similarities and Differences among Neurological Disorders

Depression and anxiety are highly prevalent in most neurological disorders and can have a major impact on the patient's disability and quality of life. However, mostly due to the heterogeneity of symptoms and the complexity of the underlying comorbidities, depression can be difficult to diagnose, resulting in limited recognition and in undertreatment. The early detection and treatment of depression simultaneously with the neurological disorder is key to avoiding deterioration and further disability. Although the neurologist should be able to identify and treat depression initially, a neuropsychiatry team should be available for severe cases and those who are unresponsive to treatment. Neurologists should be also aware that in neurodegenerative diseases, such as Alzheimer's or Parkinson's, different depression symptoms could develop at different stages of the disease. The treatment options for depression in neurological diseases include drugs, cognitive-behavioral therapy, and somatic interventions, among others, but often, the evidence-based efficacy is limited and the results are highly variable. Here, we review recent research on the diagnosis and treatment of depression in the context of Alzheimer's disease, Parkinson's disease, and strokes, with the aim of identifying common approaches and solutions for its initial management by the neurologist.

Empirical and Authoritative Classification of Neuropsychiatric Syndromes in Neurocognitive Disorders

Neuropsychiatric symptoms of neurocognitive disorders have been classified into higher-order constructs, often called neuropsychiatric syndromes. As with the general psychopathology literature, these classifications have been achieved through two approaches: empirical and authoritative. The authoritative approach relies on expert panels that condense the available evidence into operational criteria, whereas the empirical approach uses statistical methods to discover symptom patterns and possible hierarchies formed by them. In this article, the author reviews the strengths and weaknesses of both approaches using general psychopathology literature as a reference point. The authoritative approach, influenced by the DSM, has led to several sets of criteria, which could aid clinical trials, diagnostics, and communication. However, unknown reliability and the complex relationships between empirical evidence and published criteria may limit the utility of current criteria. The empirical approach has been used to explore syndrome structures on the basis of rating scales for neuropsychiatric symptoms. The structures suggested in these studies have not been replicated easily and have been limited by either small sample sizes, restricted breadth of neuropsychiatric assessment, or both. Suggestions for further development of both approaches are offered. First, neuropsychiatric symptoms and syndromes need to be studied with measures of broad scope and in large samples. These requirements are prerequisites not only for eliciting highly informative empirical classifications but also for understanding these symptoms at a more nuanced level. Second, both approaches could benefit from more transparency. Finally, the reliability of the available authoritative criteria should be examined.

Electroconvulsive Therapy for Neuropsychiatric Symptoms due to Major Neurocognitive Disorder: A Prospective, Observational Study

OBJECTIVES

Neuropsychiatric symptoms (NPSs) in those with major neurocognitive disorder (MNCD) include the responsive behaviors of agitation and aggression. Electroconvulsive therapy (ECT) has shown some effectiveness based on retrospective studies and one open label prospective study. We hypothesized that ECT will reduce NPSs between baseline and after treatment in those with medication-refractory behaviors.

METHOD/DESIGN

This Canadian prospective multicenter study included MNCD patients admitted to geriatric psychiatry units for the management of refractory NPSs. All treatment-refractory participants suffered from advanced MNCD. We conducted the Neuropsychiatric Inventory-Clinician version and the Pittsburgh Agitation Scale at baseline, and during and after the ECT course. A bitemporal or bifrontal ECT series based on dose titration to 1.5 to 2.5 times seizure threshold was administered.

RESULTS

Data were collected for 33 patients with a mean age of 73 and categorized with severe MNCD using the Functional Assessment Staging of Alzheimer's Disease scale (stages 6 and 7). The data showed a drop in mean Neuropsychiatric Inventory-Clinician version from 58.36 to 24.58 (P < 0.0001). Mean Neuropsychiatric Inventory agitation subscale dropped from 7.12 to 3.09 (P = 0.007). Mean Neuropsychiatric Inventory aggression subscale dropped from 6.94 to 0.97 (P < 0.0001). There was a concomitant significant decline in Pittsburgh Agitation Scale scores. No participants dropped out because of intolerance of ECT. One participant died from pneumonia, which did not appear related to ECT.

CONCLUSIONS

In this naturalistic study, ECT was found to be a safe and effective treatment for certain NPSs in people with MNCD. This can translate into improving quality of life.

Ecological Momentary Assessment of Depression in People With Advanced Dementia: Longitudinal Pilot Study

Background

Barriers to assessing depression in advanced dementia include the presence of informant and patient recall biases. Ecological momentary assessment provides an improved approach for mood assessment by collecting observations in intervals throughout the day, decreasing recall bias, and increasing ecological validity.

Objective

This study aims to evaluate the feasibility, reliability, and validity of the modified 4-item Cornell Scale for Depression in Dementia for Momentary Assessment (mCSDD4-MA) tool to assess depression in patients with advanced dementia.

Methods

A intensive longitudinal pilot study design was used. A total of 12 participants with advanced dementia were enrolled from an inpatient psychogeriatric unit. Participants were assessed using clinical depression assessments at admission and discharge. Research staff recorded observations four times a day for 6 weeks on phones with access to the mCSDD4-MA tool. Descriptive data related to feasibility were reported (ie, completion rates). Statistical models were used to examine the interrater reliability and construct and predictive validity of the data.

Results

Overall, 1923 observations were completed, representing 55.06% (1923/3496) of all rating opportunities with 2 raters and 66.01% (1923/2913) with at least one rater. Moderate interrater reliability was demonstrated for all items, except for lack of interest. Moderate correlations were observed between observers and patient-reported outcomes, where observers reported fewer symptoms relative to participants’ self-reports. Several items were associated with and able to predict depression.

Conclusions

The mCSDD4-MA tool was feasible to use, and most items in the tool showed moderate reliability and validity for assessing depression in dementia. Repeated and real-time depression assessment in advanced dementia holds promise for the identification of clinical depression and depressive symptoms.

Subtypes of Late-Life Depression: A Data-Driven Approach on Cognitive Domains and Physical Frailty

BACKGROUND

With increasing age, symptoms of depression may increasingly overlap with age-related physical frailty and cognitive decline. We aim to identify late-life-related subtypes of depression based on measures of depressive symptom dimensions, cognitive performance, and physical frailty.

METHODS

A clinical cohort study of 375 depressed older patients with a DSM-IV depressive disorder (acronym NESDO). A latent profile analysis was applied on the three subscales of the Inventory of Depressive Symptomatology, as well as performance in five cognitive domains and two proxies for physical frailty. For each class, we investigated remission, dropout, and mortality at 2-year follow-up as well as change over time of depressive symptom severity, cognitive performance, and physical frailty.

RESULTS

A latent profile analysis model with five classes best described the data, yielding two subgroups suffering from pure depression ("mild" and "severe" depression, 55% of all patients) and three subgroups characterized by a specific profile of cognitive and physical frailty features, labeled as "amnestic depression," "frail-depressed, physically dominated," and "frail-depressed, cognitively dominated." The prospective analyses showed that patients in the subgroup of "mild depression" and "amnestic depression" had the highest remission rates, whereas patients in both frail-depressed subgroups had the highest mortality rates.

CONCLUSIONS

Late-life depression can be subtyped by specific combinations of age-related clinical features, which seems to have prospective relevance. Subtyping according to the cognitive profile and physical frailty may be relevant for studies examining underlying disease processes as well as to stratify treatment studies on the effectiveness of antidepressants, psychotherapy, and augmentation with geriatric rehabilitation.

The Role of Neuropsychiatric Symptoms in Research Diagnostic Criteria for Neurodegenerative Diseases

Neuropsychiatric syndromes and symptoms play increasingly important roles in research diagnostic criteria for neurodegenerative disorders. Diagnostic criteria were reviewed including those for dementia, Alzheimer's disease, mild cognitive impairment, mild behavioral impairment, prodromal Alzheimer's disease, dementia with Lewy bodies, prodromal dementia with Lewy bodies, Parkinson's disease, multiple system atrophy, frontotemporal dementia, primary progressive aphasia, progressive supranuclear palsy, corticobasal degeneration, traumatic encephalopathy syndrome, Huntington' disease, amyotrophic lateral sclerorsis. All contemporary research diagnostic criteria for neurodegenerative disorders expect those for Parkinson's disease, primary progressive aphasia, multisystem atrophy and amyotrophic lateral sclerosis include neuropsychiatric phenomena as core diagnostic criteria. There are no disease-specific neuropsychiatric symptoms; apathy and disinhibition are common in tauopathies, and rapid-eye-movement sleep behavioral disorder occurs almost exclusively in synucleinopathies. Neuropsychiatric symptoms and syndromes are increasingly integrated into research diagnostic criteria for neurodegenerative disorders; they require clinician skills for recognition; their biology is better understood as their relationships to cognitive, motor, and autonomic symptoms of neurodegenerative disorders are studied.

Depression in Alzheimer's Disease: An Alternative Role for Selective Serotonin Reuptake Inhibitors?

Depression is a common co-morbidity seen in people with Alzheimer's disease (AD). However, the successful treatment of depressive symptoms in people with AD is rarely seen. In fact, multiple randomized controlled trials have shown selective serotonin reuptake inhibitors (SSRIs), the current best recommended treatment for depression, to be ineffective in treating depressive symptoms in people with AD. One explanation for this lack of treatment effect may be that depressive symptoms can reflect the progression of AD, rather than clinical depression and are a consequence of more severe neurodegeneration. This raises several questions regarding not only the efficacy of SSRIs in the treatment of depression in people with AD but also regarding the accuracy of diagnosis of depression in AD. However, there may be a rationale for the prescription of SSRIs in early AD. Even in the absence of depression, SSRIs have been shown to slow the conversion from mild cognitive impairment to AD. This may be attributed to the effect of SSRIs on the processing of amyloid-β precursor protein, which may cause a reduction in the accumulation of amyloid-β. Thus, although SSRIs may lack efficacy in treating depression in people with AD, they may hold therapeutic potential for treating and delaying the progression of AD especially if treatment begins in the early stages of AD. This article reviews the current consensus for SSRI treatment of depression in people with AD and highlights the possibility of SSRIs being a treatment option for delaying the progression of AD.

TREM1 mRNA Expression in Leukocytes and Cognitive Function in Japanese Patients with Alzheimer's Disease

BACKGROUND

Triggering receptor expressed on myeloid cells 2 (TREM2) activates the innate immune system, promotes phagocytosis by microglia, and is associated with Alzheimer's disease (AD). The possible role of a related molecule, TREM1, in AD remains unknown.

OBJECTIVE

We investigated a possible role for TREM1 in AD by determining the gene expression and methylation levels of TREM1 in leukocytes from AD patients.

METHODS

Fifty patients with AD and 50 age-matched healthy controls were enrolled. AD patients underwent a battery of neuropsychiatric tests. Peripheral blood samples were obtained from each participant, RNA and DNA were extracted, and samples were assessed for TREM1 mRNA expression and methylation rates at three CpG sites in the TREM1 promoter.

RESULTS

TREM1 mRNA expression levels in AD patients were significantly higher than those in controls (p = 0.008). TREM1 mRNA expression levels were not correlated with sex, age, duration of illness, APOE genotype, donepezil treatment, or scores of most neuropsychiatric tests. TREM1 mRNA expression levels in AD patients were correlated with the total score of the Montgomery-Åsberg Depression Rating Scale (p = 0.047, r = - 0.344). Methylation rates at the three CpG sites were significantly lower in AD patients than in controls. We also found a significant correlation between TREM1 mRNA expression and TREM1 DNA methylation rates (p < 0.001).

CONCLUSION

TREM1 may be associated with the immune responses in AD, and along with hypomethylation at CpG sites in the TREM1 promoter, may become part of a biomarker panel for AD pathogenesis.

Dissociative Experiences In Iranian Depressed Patients

In the present study, 229 major depressive disorder (MDD) patients (57.6% female; 42.4% male) were selected by convenience sampling and examined for rate of dissociative experiences. Research tools were Dissociative Experiences Scale (DES) and demographic questionnaire. Group difference examinations were performed for gender, settlement region (place of residence), and chief complaints using standard t-test, analysis of variance, and Chi-square tests as appropriate. Ordinal regression was implemented for model building. The average age of the sample was 36.78 ± 10.73. Of which, 150 (65.5%) lived in the urban and 79 (34.5%) in the rural areas. The chief complaint of the 146 patients (63.8%) was psychiatric symptoms specific to MDD, and the remaining 83 patients (36.2%) had physical symptoms. The average DES score was 10.59 ± 13.59; and a significant mean DES score differences (P < 0.01) between patients' referred to physician for physical versus psychological complaints (physical: 23.61 ± 14.39; psychological: 3.19 ± 4.5) and geographic settlements (rural: 19.58 ± 15.13; urban: 5.86 ± 9.86) were observed. This study highlights the presence of subtype within MDD patients with significant dissociative tendencies. Given the relationship between trauma history and dissociation, this subgroup could be considered as probable cases with childhood history of abuse, lending to use dissociation as a defense mechanism. Given the evidence for promising results of trauma-focused psychotherapy in treating such patients, paying proper attention to childhood history of depression especially with somatization may minimize pain and suffering of these individuals overtime.

A 24-week double-blind placebo-controlled study of the efficacy and safety of the AMPA modulator S47445 in patients with mild to moderate Alzheimer's disease and depressive symptoms

Introduction

S47445 is a novel positive allosteric modulator of alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors that may emerge as a favorable candidate for the symptomatic treatment of cognitive and depressive disorders in patients suffering from Alzheimer's disease (AD) of mild to moderate severity and with depressive symptoms.

Methods

For this double-blind, placebo-controlled 24-week phase II trial, 520 outpatients aged between 55 and 85 years, with probable AD at mild to moderate stages (a Mini-Mental State Examination score of 24-15 inclusive) and exhibiting depressive symptoms (Cornell Scale for Depression in Dementia [CSDD] ≥ 8) were recruited in twelve countries and randomized to 3 doses of S47445 (5-15-50 mg) or placebo. The primary end point was the change from baseline in the 11-item Alzheimer's Disease Assessment Scale-Cognitive subscale (ADAS-Cog) total score at week 24. Secondary measures included the Disability Assessment for Dementia, Mini-Mental State Examination, ADAS-Cog 13-item, CSDD, Clinical Global Impression of Change (Alzheimer's Disease Cooperative Study-CGIC), Neuropsychiatric Inventory (NPI), and safety criteria.

Results

Baseline characteristics were comparable between the 4 groups. After 24 weeks, no statistically significant treatment difference was demonstrated between S47445 (5, 15 or 50 mg/d) and placebo on cognition (ADAS-Cog), function (Disability Assessment for Dementia), or depressive symptoms (CSDD). An improvement on neuropsychiatric symptoms assessed by NPI was evidenced at the lower dose 5 mg/d (Δ -2.55, P = .023, post hoc analysis) compared to placebo. CSDD and total NPI scores improved in all groups including placebo. There were no specific and/or unexpected safety signals observed with any of the S47445 doses.

Discussion

S47445 administered for 24 weeks was safe and well tolerated by patients with mild to moderate AD; the compound did not show significant benefits over placebo on cognition, function, or depressive symptoms.